Telephone-transmitter



(No Model.) J. H. ROGERS;

TELEPHONE TRANSMITTER.

N0.-599,867. PatentedMar. 1,1898

ATTORNEY UNITED STATES PATENT OFFICE.

JAMES HARRIS ROGERS, OF BLADENSBURG, MARYLAND.

TELEPHONE-TRANSMITTER.

SPECIFICATION forming part of Letters Patent No. 599,867, dated. March 1, 1898.

Application filed March 9, 1897- Serial No. 626,572. (No model.)

To aZZ whom it may concern:

Be it known that I, JAMES HARRIS ROGERS, a citizen of the United States, and a resident of Bladensburg, in the county of Prince Georges and State of Maryland,have invented a certain new and useful Telephone-Transmitter, of

vibrations or undulations of the air caused by vocal or other sounds.

The object of this invention is the production of a reliable, convenient, and inexpensive transmitter; and to this end the invention consists in the construction, combination,and arrangement of parts hereinafter fully described, and set forth in the claims.

In the accompanying drawings, which form a part of this specification, Figure 1 represents in side elevation one form of the improved transmit-ter. Fig. 2 represents in vertical section the effective parts of the transmitter and also shows diagrammatically its connection in circuit. Fig. 3 shows a modification of that form of transmitter adapted for use upon a table or desk. Fig. 4 represents a modification in the transmitter and shows it attached to a wall-bracket. Fig. 5 represents a modification in the construction of the electrodes.

In transmitters heretofore constructed diaph'ragms or membranes for receiving the impact of sound-waves have been connected to movable electrodes, but have been confined in one way or another within casings of various sorts and have been generally of very limited area. They have also generally been associated with a tube or mouthpiece for di-, recting the sound-waves thereagainst. In the present invention that upon which the sound-waves impinge or against which they are directed is entirely exposed and free to vibrate in response to the impinging waves whatever their form, source, or velocity. In so far as this part receives the sound-waves it resembles the diaphragm or membrane of the ordinary transmitter, but its construc tion operation, and effectiveness being materially different from the ordinary diaphragm it has been deemed advisable to give to it the name of target or sounding-board.

In the drawings, A indicates this soundingboard or target, which is connected to a movable part or member of the electrodes of the transmitter, and consists of some light elastic material, such as celluloid. Said movable part -or member of the electrodes may be made in various forms and adapted to cooperate with the fixed or otherwise supported -electrode or electrodes in various ways, four different forms therefor being indicated in the drawings at B B B B .In Fig. 2 the part B of the electrodes acts to span the portions 0 and O. of the fixed electrode, these portions being insulated from one another, as indicated, and connected in the local circuit B, which, as usual, has communication with the line E through the in ductorium F.

In Fig. 3 the part B is indicated as resting directly upon the Hat end of the fixed electrode C the part B serving in this instance as one of the electrodes and being connected to the circuit of the transmitter by means of the insulated conductor G, which in this form of the instrument is passed through the fixed electrode and engages at its lower end with a spring I-I, electrically connected to one of the binding-posts of the instrument, the electrode C being connected to the other binding-post, as indicated. The conductor G also serves as a projection from B into C for holding the former in place upon the latter.

In Fig. 4: the part B is shown suspended by the conductor 1 from the lower end of the wall-bracket J. Resting upon this or secured to the bracket I and engaging with the electrode B? is the cooperating electrode 0?, from which the other terminal of the transmittercircuit leads through the bracket J.

In Fig. 5 the electrode B has its lower end made in spheroidal form and is placed or supported as a projection from B in a cup in the upper end of the fixed electrode 0 The target Ais secured to the electrode B in any suitable manner and the circuit-terminals of the transmitter are connected in any suitable way I to the electrodes B and C The target or sounding-board is by preference made of some thin light material which is not detrimentally aifected in any way by moisture. Celluloid has been used for this purpose, but other similar light elastic substances will do as well. The target or sounding-board may be of any suitable shape and secured to the movable member of the electrodes in any suitable manner, but in practice a conical or skirt-like form, such as illustrated, has been found preferable. It is also preferable to attach this conical soundingboard by its apex to the movable electrode and to have it depend therefrom. It might, however, in the construction of apparatus shown in Fig. 3, be inverted, so that the base of the cone would be uppermost. It is believed that the conical form is most efficient because of its not having any particular tone of its own, but being capable because of its graded diameters to respond to any and all tones.

If it is desired simply to obtain an extended area for the sounding-board regardless of its inherent tone, it may assume a cylindrical form, as indicated in Fig. 4.

If the sounding-board is made of considerable size, and it may be made of any desired size, the construction represented in Fig. 3 is perhaps the best, since therein a portion of the Weight of the electrode B and the sounding-board may be sustained by the spring II. Any suitable tension device, such as indicated at K, may be added to this spring to vary the degree of pressure between the electrodes B and C The electrodes may also be made of any suitable material, but they are preferably made of carbon.

What I claim as my invention is 1. In a telephone-transmitter, the combination with a suitable support, of a fixed electrode projecting therefrom, a movable electrode mounted upon the fixed electrode, and asounding-board of light elastic material, such as celluloid, attached to and depending from the movable electrode in a conical or skirt-like form so as to produce an extended surface adapted to receive sound- Waves from all sides and to convey the motion produced thereby to the movable electrode, as and for the purpose set forth.

2. In a telephone-transmitter, the combination with a fixed electrode, of a movable electrode mounted thereon and having a projection entering the fixed electrode to hold it in place on the latter, and an elastic conical or skirt-like sounding-board or target depending from the movable electrode for the purpose set forth.

3. In a telephone-transmitter, the combination with a fixed electrode, of a movable electrode mounted thereon, a sounding-board or target attached to the latter, an insulated conductor extending from the movable electrode through the fixed electrode, and a spring forming one terminal of the circuit through the transmitter and serving as a partial support for said conductor, the movable electrode and the sounding-board or target.

Signed at \Vashington, in the District of Columbia, this 1st day of March, A. D. 1897.

JAMES HARRIS ROGERS.

IVitnesses:

JOSEPH L. ROGERS, JAMES C. ROGERS. 

